Olympic Arms used the venue of the biggest firearms trade show in America to announce our latest new product: The MPR 308-15 rifle. The MPR (Multi-Purpose Rifle) carrys the model number 308-15 for good reason. The lower of the MRP 308-15 is a billet lower receiver designed to accomodate both mil-spec AR15 uppers in all calibers, as well as the new Olympic Arms .308 uppers designed for the MRP lower.